What to Expect from COVID
A lot of numbers are being generated these days on the Coronavirus, so I thought I would play around with them and get some estimates together on what to expect in the coming year. I know something about probabilities and formal studies, but I am not a statistician. Nevertheless, I will try to assemble some of the data out there, and see where it takes us.
COVID vs. Flu - How bad IS the Flu, Really?
People know what the Flu is, and generally what to expect from it. Naturally, people want to compare COVID to the Flu as a way to see how bad COVID is.
It is extremely difficult to find data on the flu season that is created from hard numbers, vs the statistical models that seem to be created from whole cloth at the US Dept of Health. Data from Quebec suits my purposes very well– 75% of Quebec residents do not get a flu shot. Their health department keeps statistics on how many people are tested for flu each year, and how many of those tests are positive for flu. Let’s take a look:
https://www.google.com/search?q=population+of+quebec&oq=population+of+quebec&aqs=chrome..69i57j0l7.4579j0j15&sourceid=chrome&ie=UTF-8
Quebec has 8.485 Million residents. If only 25% of them get a flu shot, this means that 6.354 Million persons have not had a flu shot. Let’s assume that no one who got a flu shot in Quebec came down with flu, and just use 6.354 Million as the pool of possible flu candidates.
https://www.inspq.qc.ca/influenza
Of this 6.3 Million, 100,800 people became sick enough that they went to hospital to be tested for flu. About 16% of these were confirmed positive for flu–or about 15,120 cases.
Sadly, 300 of them died of the flu.
300 deaths out of 15,120 confirmed cases is a death rate of 2%–But its 2% of those who were sick enough to seek testing, and confirmed by testing to have had the flu.
What are the chances that an unvaccinated Quebec Resident would have gotten the Flu that year? Well, its 15,120/6,300,000, or about 0.24%
Let’s say there were twice as many flu cases in Quebec that year as people who tested positive. Even if that is the case, the prevalence of flu in Quebec, in that non-pandemic year, was 30,240/6,300,000, or about 0.5%
So for the flu in Quebec in that non-pandemic year, we can estimate that:
0.5% had the flu.–Prevalence of one half percent.
0.25% had flu bad enough to go to hospital for testing.
2% of bad flu patients have died.
0.0005% of non-vaccinated Quebec (that’s 2% of the 0.25%) died from bad flu.
How can we compare this to COVID?
The COVID statistics that pop up in a window on CNN every night list only the numbers of confirmed cases and the numbers of deaths. Today, there are 7,856,321 cases, and 215,882 deaths. There are about 330 Million US Residents. Making this into percentages;
12.4% have COVID– See below for how this prevalence was estimated.
2.4% have had COVID bad enough to go to hospital for testing (7.8M/330M)
2.8% of those with bad COVID have died (216K/7.856M).
0.0006% of the US Population died from bad COVID.
One unfortunate cruise ship can help us estimate the prevalence of COVID--
https://www.psychiatrictimes.com/view/covid-19-has-mortality-rate-declined
On this hapless cruise to Antarctica, there were 217 Passengers.
128 eventually tested positive for COVID
104 had no symptoms.
16 had only fever and mild symptoms.
4 had very severe symptoms but no intubation.
4 were intubated, and of these 4, one died.
Only 24 of the 128 patients had symptoms. That’s about 19%.
Dividing the 7,856,321 known patients by 0.19 yields about 41 Million cases in the US.
41M/330 M gives us an estimated prevalence in the US of about 12.4%.
COVID vs. FLU
Comparing the estimated percentages above,
COVID is already 25 X more prevalent than flu;
COVID is 10X more likely than Flu to make someone sick enough to go to hospital.
COVID is 1.4 X more likely to kill than Flu.
Looks pretty bad so far. What else can the numbers tell us?
In the US, known COVID cases double every 4 months;
https://www.cnn.com/interactive/2020/health/coronavirus-us-maps-and-cases/
If we start with the estimated prevalence of 41M/330M, we can figure out how many months until COVID reaches full saturation;
Oct 2020 41M
Feb 2021 82M
Jun 2021` 164M
Oct 2021 328M
So it could be another year until the virus has gotten everywhere it can go in the US.
Of these 328 M cases, only 19%, or 62M, will be symptomatic.
When you see the case count on CNN at 62M, you know the US population is saturated.
When will the COVID Death Rate be the same as the Flu?
Infecting organisms tend to kill a smaller percentage of people over time, and this has been true for COVID, so far.
While watching the US statistics on COVID that come to CNN via Johns Hopkins University, I got into the habit of dividing the deaths by the total number of detected cases. It was something like 5.5% in April 2020. I remember early estimates of COVID lethality, some as high as 10 to 11% in the original Chinese city. Putting that in a table, we can see that the COVID death rate among the very sick goes down by half about every 6 months:
11/2019 11%
04/2020 5.5%
10/2020 2.8%
(04/2021 1.4%)
So, sometime between now and April, the death rate for COVID in the very sick will match that of the Flu.–If this is a good model!
FINAL COMMENTS
So–It will be another year before COVID has spread as far as it can. In 4 more months, it will be only as deadly as the flu. Places that have avoided high amounts of COVID just need to stay isolated for about another 6 months. If they do so, the virulence will be way down, and they will have missed the worst of the Pandemic.
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